tests/stress/rest-elements.js

   1 function shouldBe(actual, expected) {
   2     if (actual !== expected)
   3         throw new Error('bad value: ' + actual);
   4 }
   5
   6 function shouldThrow(func, errorMessage) {
   7     var errorThrown = false;
   8     var error = null;
   9     try {
  10         func();
  11     } catch (e) {
  12         errorThrown = true;
  13         error = e;
  14     }
  15     if (!errorThrown)
  16         throw new Error('not thrown');
  17     if (String(error) !== errorMessage)
  18         throw new Error(`bad error: ${String(error)}`);
  19 }
  20
  21 function testSyntaxError(script, message) {
  22     var error = null;
  23     try {
  24         eval(script);
  25     } catch (e) {
  26         error = e;
  27     }
  28     if (!error)
  29         throw new Error("Expected syntax error not thrown");
  30
  31     if (String(error) !== message)
  32         throw new Error("Bad error: " + String(error));
  33 }
  34
  35 (function () {
  36     var [a, b, ...c] = "Cocoa";
  37     shouldBe(a, 'C');
  38     shouldBe(b, 'o');
  39     shouldBe(JSON.stringify(c), String.raw`["c","o","a"]`);
  40 }());
  41
  42 (function () {
  43     var [a, b, ...c] = "Co";
  44     shouldBe(a, 'C');
  45     shouldBe(b, 'o');
  46     shouldBe(JSON.stringify(c), String.raw`[]`);
  47 }());
  48
  49 (function () {
  50     var [a, b, ...c] = "C";
  51     shouldBe(a, 'C');
  52     shouldBe(b, undefined);
  53     shouldBe(JSON.stringify(c), String.raw`[]`);
  54 }());
  55
  56 (function () {
  57     var a, b, c;
  58     [a, b, ...c] = "Cocoa";
  59     shouldBe(a, 'C');
  60     shouldBe(b, 'o');
  61     shouldBe(JSON.stringify(c), String.raw`["c","o","a"]`);
  62 }());
  63
  64 (function () {
  65     var a, b, c;
  66     [a, b, ...c] = "Co";
  67     shouldBe(a, 'C');
  68     shouldBe(b, 'o');
  69     shouldBe(JSON.stringify(c), String.raw`[]`);
  70 }());
  71
  72 (function () {
  73     var a, b, c;
  74     [a, b, ...c] = "C";
  75     shouldBe(a, 'C');
  76     shouldBe(b, undefined);
  77     shouldBe(JSON.stringify(c), String.raw`[]`);
  78 }());
  79
  80 (function ([a, b, ...c]) {
  81     shouldBe(a, 'C');
  82     shouldBe(b, 'o');
  83     shouldBe(JSON.stringify(c), String.raw`["c","o","a"]`);
  84 }("Cocoa"));
  85
  86 (function ([a, b, ...c]) {
  87     shouldBe(a, 'C');
  88     shouldBe(b, 'o');
  89     shouldBe(JSON.stringify(c), String.raw`[]`);
  90 }("Co"));
  91
  92 (function ([a, b, ...c]) {
  93     shouldBe(a, 'C');
  94     shouldBe(b, undefined);
  95     shouldBe(JSON.stringify(c), String.raw`[]`);
  96 }("C"));
  97
  98 testSyntaxError(String.raw`var [a, ...b, c] = 20`, String.raw`SyntaxError: Unexpected token ','. Expected a closing ']' following a rest element destructuring pattern.`);
  99 testSyntaxError(String.raw`var [a, ...b,] = 20`, String.raw`SyntaxError: Unexpected token ','. Expected a closing ']' following a rest element destructuring pattern.`);
 100 testSyntaxError(String.raw`var [a, ...b,,] = 20`, String.raw`SyntaxError: Unexpected token ','. Expected a closing ']' following a rest element destructuring pattern.`);
 101 testSyntaxError(String.raw`var [a, ...b = 20] = 20`, String.raw`SyntaxError: Unexpected token '='. Expected a closing ']' following a rest element destructuring pattern.`);
 102 testSyntaxError(String.raw`var [a, ...[b, c]] = 20`, String.raw`SyntaxError: Unexpected token ']'. Expected identifier for a rest element destructuring pattern.`);
 103 testSyntaxError(String.raw`var [a, ...{ b, c }] = 20`, String.raw`SyntaxError: Unexpected token ']'. Expected identifier for a rest element destructuring pattern.`);
 104
 105 testSyntaxError(String.raw`(function ([a, ...b, c]) { })`, String.raw`SyntaxError: Unexpected token ','. Expected a closing ']' following a rest element destructuring pattern.`);
 106 testSyntaxError(String.raw`(function ([a, ...b,]) { })`, String.raw`SyntaxError: Unexpected token ','. Expected a closing ']' following a rest element destructuring pattern.`);
 107 testSyntaxError(String.raw`(function ([a, ...b,,]) { })`, String.raw`SyntaxError: Unexpected token ','. Expected a closing ']' following a rest element destructuring pattern.`);
 108 testSyntaxError(String.raw`(function ([a, ...b = 20,,]) { })`, String.raw`SyntaxError: Unexpected token '='. Expected a closing ']' following a rest element destructuring pattern.`);
 109 testSyntaxError(String.raw`(function ([a, ...[b, c]]) { })`, String.raw`SyntaxError: Unexpected token ']'. Expected identifier for a rest element destructuring pattern.`);
 110 testSyntaxError(String.raw`(function ([a, ...{ b, c }]) { })`, String.raw`SyntaxError: Unexpected token ']'. Expected identifier for a rest element destructuring pattern.`);
 111
 112 shouldThrow(function () {
 113     [a, ...b, c] = 20;
 114 }, "ReferenceError: Left side of assignment is not a reference.");
 115
 116 shouldThrow(function () {
 117     [a, ...b,] = 20
 118 }, "ReferenceError: Left side of assignment is not a reference.");
 119
 120 shouldThrow(function () {
 121     [a, ...b,,] = 20
 122 }, "ReferenceError: Left side of assignment is not a reference.");
 123
 124 shouldThrow(function () {
 125     [a, ...b = 20] = 20
 126 }, "ReferenceError: Left side of assignment is not a reference.");
 127
 128 (function () {
 129     var a, b, c;
 130     [a, b, ...[...c]] = "Cocoa";
 131     shouldBe(a, 'C');
 132     shouldBe(b, 'o');
 133     shouldBe(JSON.stringify(c), String.raw`["c","o","a"]`);
 134 }());
 135
 136 (function () {
 137     var a, b, c, d, e, f;
 138     [a, b, ...{ 0: c, 1: d, 2: e, 3: f }] = "Cocoa";
 139     shouldBe(a, 'C');
 140     shouldBe(b, 'o');
 141     shouldBe(c, 'c');
 142     shouldBe(d, 'o');
 143     shouldBe(f, undefined);
 144 }());
 145
 146 (function () {
 147     var a, b, c, d, e;
 148     [a, b, ...[c, d, ...e]] = "Cocoa";
 149     shouldBe(a, 'C');
 150     shouldBe(b, 'o');
 151     shouldBe(c, 'c');
 152     shouldBe(d, 'o');
 153     shouldBe(JSON.stringify(e), String.raw`["a"]`);
 154 }());
 155
 156 function iterator(array) {
 157     var nextCount = 0;
 158     var returnCount = 0;
 159     var original =  array.values();
 160     return {
 161         [Symbol.iterator]() {
 162             return this;
 163         },
 164
 165         next() {
 166             ++nextCount;
 167             return original.next();
 168         },
 169
 170         return() {
 171             ++returnCount;
 172             return { done: true };
 173         },
 174
 175         reportNext() {
 176             return nextCount;
 177         },
 178
 179         reportReturn() {
 180             return returnCount;
 181         }
 182     };
 183 };
 184
 185 (function () {
 186     var iter = iterator([1, 2, 3]);
 187     var [...a] = iter;
 188     shouldBe(iter.reportNext(), 4);
 189     shouldBe(iter.reportReturn(), 0);
 190     shouldBe(JSON.stringify(a), String.raw`[1,2,3]`);
 191 }());
 192
 193 (function () {
 194     var iter = iterator([1, 2, 3]);
 195     var [a, b, ...c] = iter;
 196     shouldBe(iter.reportNext(), 4);
 197     shouldBe(iter.reportReturn(), 0);
 198     shouldBe(a, 1);
 199     shouldBe(b, 2);
 200     shouldBe(JSON.stringify(c), String.raw`[3]`);
 201 }());
 202
 203 (function () {
 204     var iter = iterator([1, 2, 3]);
 205     var [a, b, c, d, ...e] = iter;
 206     shouldBe(iter.reportNext(), 4);
 207     shouldBe(iter.reportReturn(), 0);
 208     shouldBe(a, 1);
 209     shouldBe(b, 2);
 210     shouldBe(c, 3);
 211     shouldBe(d, undefined);
 212     shouldBe(JSON.stringify(e), String.raw`[]`);
 213 }());
 214
 215 (function () {
 216     var iter = iterator([1, 2, 3]);
 217     var a, b;
 218     [...[a, b]] = iter;
 219     shouldBe(iter.reportNext(), 4);
 220     shouldBe(iter.reportReturn(), 0);
 221     shouldBe(a, 1);
 222     shouldBe(b, 2);
 223 }());